My point is that when the roads are full, you have to build alternative transportation off the roads, which means either below them or above them. It's not as if elevated rail were really a new idea.

(Purportedly a view under the Baltimore el, pre-1950)

It turns out that elevated bikeways aren't novel either! (more at the link)

And there's another co-benefit: an emerging car-free commons.

The solutions to our problems lie in alternative lightweight
transportation on alternative route networks that minimally intersect
with the existing road network and as much as possible are human-powered
or externally powered (like electric trains).
The best way to achieve this is by putting trains and bicycles above
the car traffic. This offers an opportunity to develop delightful
above-grade pedestrian and recreation facilities as well.

Blegging for Medium.com likes, please and thanks! I sweated over this piece, and it doesn't target my usual audience.